AjaxControlToolkit.TabContainer.RaisePostDataChangedEvent C# (CSharp) Method

        protected override void RaisePostDataChangedEvent()
        {
            // If the tab index changed
            if(LastActiveTabIndex == ActiveTabIndex)
                return;
            // Saving last active tab index
            LastActiveTabIndex = ActiveTabIndex;

            // The event fires only when the new active tab exists and has OnDemandMode = Always or
            // when OnDemandMode = Once and tab wasn't loaded yet
            var activeTab = this.ActiveTab;
            if(activeTab != null && (activeTab.OnDemandMode == OnDemandMode.Always || activeTab.OnDemandMode == OnDemandMode.Once && !activeTab.WasLoadedOnce))
                OnActiveTabChanged(EventArgs.Empty);
        }